Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

CLEAR OVERFALL. 263 OF ENGINEERING FOBMULÆ. Rise of Water caused by Weirs in Rivers DROWNED WEIR. O' 1 • 25 d \ —- I as a nearer H ) w = Quantity of water in cubic feet per second passing over the weir. B = Breadth of weir in feet. H = Height of water above the top of the wen. D = Height of water above the top of the weir in a drowned weir. d = Level of tail water above top of weir in a drowned weir. 3 / W2 . X 1 H = approximately. D - H + d as a rough approximation. * / 1 • /7 \ = (H + <D “ d ( i “ approximation. Depth of the Water Cushion for Weirs. (Dyas.) d = Depth of fall from surface to sur- face. II = Height of water over top ot weir. i= Depth of water cushion. a- = H + 4/ft \/d.